The present invention concerns an improvement of the devices containing a plurality of toothed blades of flanked keys that may be selected and pulled out one by one.
The prior art already knows Italian patent no. 1232242, filed by the same applicant, as well as international publication no. WO 91/03185, granted as U.S. Pat. No. 5,232,036 and as European Patent no. 0442970, concerning a device containing a plurality of toothed blades of flanked keys that may be selected and pulled out one by one, and in which keys are placed in reciprocal contact, inserted in a horizontally movable slide inside said container, wherein the position of the keys is determined by the contact between the relative walls, by the vertical back of the blade that gets into a corresponding seat of the slide, and by the groove on the upper edge of the blade by means of which it gets hooked to the square guide beam of the top.
In the realization of the device according to mentioned patent, some difficulties have shown in its working:
when the blade is selected and the upper side of the container is turned downwards, the toothed edge of the blade tends to get stuck in the longitudinal slit in the middle of the top, thus blocking the transversal movement of the slide;
sometimes it happens that the necessary, even if very little plays, between one blade and the other get summed preventing the pulling out thereof because the point of the blade turns away from the longitudinal axis and finds an obstacle against the edge of the outlet slit, in spite of the rounding of the slit""s edges and of the point of the blade;
when it happens that blades of different lengths (corrsponding to locks with a three or four pin block, wherein said pins are shorter than the more common five pins) are flanked in the slide, it may occur that one blade flanked to a shorter one may be pulled out of the container but often finds an obstacle when it must be placed back: infact, the shorter blade lacks the lateral support of the pulled out blade and when opening the lock, the rotation of the container frequently causesxe2x80x94due to gravityxe2x80x94the deviation of the short blade into the lateral space that now is free, and thus its point invades the running of the pulled out blade and blocks the same.
The disadvantages of mentioned patent are shown in the enclosed FIGS. 1 and 2, in which respectively the theoric and regular movement of the five-pin blades is shown as well as the deviation and the following blocking of the return of the pulled out blade.
It is the aim of the present improvement to completely solve above mentioned working difficulties.
The aim set forth is reached by means of the improvement according to the present invention, consisting of blades guided by parallel, equidistant walls obtained inside said slide, preferably of the same height of the blades between which they are put, for the precision of the pulling out and return of said blades; furthermore, each blade shows a groove with a preferably triangular section along the whole length of the resting edge against the bottom of the slide, for the precise sliding along the ribs of equal sections obtained thereon.